src: switch to clap for argument parsing

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

src/main.rs

@@ -1,3 +1,5 @@
+use anyhow::anyhow;
+use clap::{crate_version, App, AppSettings, Arg};
 use git2::Repository;
 use serde::{Deserialize, Serialize};
 use std::{
@@ -15,26 +17,54 @@ struct PersistableRepo {
 }
 
 fn main() -> anyhow::Result<()> {
-    let dir = match std::env::args().nth(2) {
+    let matches = App::new("hcctl")
-        Some(d) => d,
+        .about("Command-line tool for backing up and restoring multiple Git repositories from a directory")
-        None => {
+        .version(crate_version!())
-            println!("Usage:\n  gitice <command> <dir>\n");
+        .setting(AppSettings::ColoredHelp)
-            return Ok(());
+        .setting(AppSettings::DeriveDisplayOrder)
-        }
+        .setting(AppSettings::SubcommandRequiredElseHelp)
-    };
+        .subcommand(
+            App::new("freeze")
+            .about("Generate a gitice.lock file with all the repositories in the given directory")
+            .args(&[Arg::with_name("directory")
+                .help("Directory to look for Git repos in")
+                .required(true)
+                .index(1)]),
+            )
+        .subcommand(
+            App::new("thaw")
+                .about("Given a gitice.lock and a directory, clones back all the repositories from the lockfile in the directory")
+                .args(&[
+                    Arg::with_name("directory")
+                    .help("Directory to restore repositories in")
+                    .required(true)
+                    .index(1),
+                    Arg::with_name("lockfile")
+                    .help("The lockfile to restore repositories from")
+                    .short("l")
+                    .long("lockfile")
+                    .required(false)
+                    .default_value("gitice.lock")
+                    ]),
+        )
+        .get_matches();
 
-    // temporary solution to support both freezing and thawing
+    match matches.subcommand() {
-    match std::env::args().nth(1).as_ref().map(|s| &s[..]) {
+        ("freeze", m) => freeze_repos(m.unwrap().value_of("directory").unwrap())?,
-        Some("freeze") => freeze_repos(dir),
+        ("thaw", m) => {
-        Some("thaw") => thaw_repos(dir),
+            let m = m.unwrap();
-        _ => {
+            thaw_repos(
-            println!("Usage:\n  gitice <command> <dir>\n");
+                m.value_of("directory").unwrap(),
-            Ok(())
+                m.value_of("lockfile").unwrap(),
+            )?
         }
+        (cmd, _) => return Err(anyhow!("unknown subcommand: {}", cmd)),
     }
+
+    Ok(())
 }
 
-fn freeze_repos(dir: String) -> anyhow::Result<()> {
+fn freeze_repos(dir: &str) -> anyhow::Result<()> {
     let mut repos: HashMap<String, PersistableRepo> = HashMap::new();
     for entry in WalkDir::new(dir.clone()).into_iter().filter_map(|e| e.ok()) {
         if entry.file_type().is_dir() {
@@ -75,14 +105,20 @@ fn freeze_repos(dir: String) -> anyhow::Result<()> {
         };
     }
     fs::write("gitice.lock", toml::to_string(&repos)?).expect("could not write to lockfile!");
+    println!(
+        "Successfully generated lockfile with {} repos",
+        &repos.len()
+    );
     Ok(())
 }
 
-fn thaw_repos(dir: String) -> anyhow::Result<()> {
+fn thaw_repos(dir: &str, lockfile: &str) -> anyhow::Result<()> {
-    let lockfile = fs::read_to_string("gitice.lock").expect("unable to read lockfile!");
+    let lockfile =
+        fs::read_to_string(lockfile).expect(&format!("unable to read lockfile from {}", lockfile));
     let repos: HashMap<String, PersistableRepo> = toml::from_str(&lockfile)?;
 
     for (name, repo) in repos {
+        println!("Cloning {} from {}", &name, &repo.remote_url);
         let output = Command::new("git")
             .args(&[
                 "clone",